Forging machine



March 16, 1943. L. M. BROWN I 2,313,722

' FORGING MACHINE Filed Sept. 26, 1940 Patented Mar. 16, 1943 FORGINGMACHINE Linwood M; Brown, Pittsburgh, Pa., assignor to L. M. Brown,Inc., a corporation of Delaware Application September'Zli, 1940, SerialNo. 358,449

1 Claim.

My invention relates to forging machines, par ticularly to machines forforging points upon cutter bits that areused inmining machinery,

A few years ago it was discovered that, if the dies of a bit-forgingmachine were caused to strike the work with blows similar in charactertmtheblbws delivered by a blacksmiths ham mer, the grain structure ofthe metal in the forgedpoints was far superior to the grain structure ofthe bits whose points were forged be tween rolls, or between thedies ofa press. Indeed, I have found. the usual roll'and press machines to beentirely inadequate for the pointing of: bits that are formed of thehard and tough steels that have been developed in recent years, thisbeing particularly true in the case of the steel alloy disclosed inUnited States Letters Patent; No. 1,615,323, granted to me' s'eptember20, 192.7, and rei'ssued Octob'er 28, 1930. In the forging or pointingof" bits of my steel alloy, it

seems that the'hammer type machine-is the-only machine that" can do thejob with entire satisfaction. I l l A hammer type machine of the" sort.I have in mind is illustrated: and described in- United States LettersPatent No. 1,818,601, August 11, 1931.

machine the heatedbit blank to be pointed is positioned within thecorner formed by the in tersecting legs of the L. The machineincludestwo" forging" dies that are reciprocated alternately, one die beingreciprocated in. a plane normal to one leg of the anvil and the otherin.

a planernormal toithe other leg of the anvil, and the twoso-reciprocated dies forge a point on the bit blank sustained inposition in the corner of the anvil.

Each of the reciprocating dies is carried upon the upper end of a leverarm which is mounted, at a point intermediate its opposite ends, upon apivot shaft; a rotated cam is organized adjacent to the lower end ofeach lever arm, and tension springs are arranged to exert rotativestress upon the lever arms, in such manner that the lower ends of thelever arms are held in contact with said cams severally. The rotatingcams, thus engaged by the lower ends of the lever arms, operatealternately to swing the lever arms through a determined angularinterval against the tension of the springs, and then to release thelever arms to the influence of such tension, with the consequence thatthe arms are angularly oscillated on their pivots. It will be understoodthat the angular movement of each dated The anvil of this machine isoft-shape in plan, and in theoperation of the arm inione ofits-alternatedirections of oscillation-is effected bypositive action ofits associate cam, while the movement of the arm in opposite directionis effected by spring tension. The structure and'organization of theparts are such that the dies are alternately. propelled against theanvil under the influence of spring tension, whereby the desired hammeraction is obtained, and superior grain structure in the forged? meta isrealized.

In the operation of a machine of this sort, I have experienced greatdifli'culty in providing lever arms that will withstand'the violentshocks imparted thereto asthe forging dies are repeatedly and rapidlydriven against the anvil. The invention consists in a. lever armstructure that is particularly effective in overcoming this difiiculty,and in providing improved operation of the machine'as awhole.

Allie-oscillating. lever'arm' of the invention is illustrated. in theaccompanying drawing, in which:

Fig. I isv a view of the lever arm in side elevation; with certain ofthe essential elements of the forging machine (in which the lever armwill be assembled for'service) shown schematically, partly in sideelevation and partly in vertical. section;

Fig. II is a viewof the lever arm and the forging die carried thereby inplan from. above;

Fig. III. is a View of the lever arm in crosssection, .on the planeIII-I-II of: Fig. I;

In theschematic illustration of Fig. I the L- shaped anvil 2" of abit-forging machine appears 4 fragmentarily and invertical sectionthrough one leg of the L. Only one of the two dies 5 that cooperate withsuch anvil in forging a point on a bit 4 is shown, together with thelever arm 3 that carries the die, and the power-rotated cam II andspring l5 that effect reciprocation of the die. Inasmuch as theinvention consists in improvements in the structure and organization ofthe die-carrying lever arms of such machine, the showing in the drawingherein will suffice, particularly in View of the fact that reference maybe had to the above-noted Patent No. 1,818,601 for such features ofgeneral machine assembly as may be of interest. Before proceeding withthe description of the lever-arm structure of the invention, it may bementioned that, Whereas each of the two forging dies of the machine ofthe patent is united to the distal end of its associate lever arm in apin-and-slot connection, with the die arranged to reciprocate in aslideway, in the structure of V myinvention each die is rigidly securedupon the distal end of its associate lever arm, and is adapted tooperate without the need of a guiding slideway.

Turning to the structure in which the invention is centered: The leverarm 3 is formed of a rigid rocker member or hub 6, a rigid arm portionI, and an elastic helve portion 8, all united in rigid assembly. Therocker member or hub 6 is keyed to a shaft 9 that is trunnioned at itsopposite ends in the frame (not shown) of the forging machine, and suchshaft provides the axis or pivot on which the lever arm is oscillated.The arm portion I is integrally formed of metal with the rocker hub 6;such arm portion '1, extending downward from the axis on which the leverarm 3 is adapted to oscillate, carries a wear-resisting block ID thatrides the periphery or face of the cam I I, which cam is keyed to thepower-rotated shaft l2 of the forging machine. The helve 8 is secured tothe rocker hub, by means of a socket portion 1 3 whose side walls aresubstantially par allel as shownthe lower end of the helve being driveninto the bore of such socket portion under a pressure of several tons.While the resulting compression of the end of the helve in the socketportion affords absolute security of assembly, a bolt I4 is employed asan additional precaution .against the helve becoming loose While theforging machine is in operation. 7

The forging die is secured to the upper end of the helve, the body ofsuch die including a bore 80 that receives the upper end of the helve.The end of the helve is secured with a force-fit in the bore of the die,and a tapered pin 8| is driven a through the assembly to insuresecurity.

As already indicated, the rocker hub 6, arm portion I, and socketportion l3 are integrally formed of a rigid and sturdy material, such asforged or cast steel, while the helve is formed of suitableimpact-absorbing. material, preferably a wood such as hickory. Thetension spring l5 exerts rotative stress upon the lever arm 3; and suchspring, tending to swing the lever arm in clockwise direction, isefiective to hold the block It) at the distal end of arm portion 1against the cam I l. The spring is tensioned between a fixed portion ofthe forging machine frame (not shown) and the end of an arm [6 securedto the pivot shaft 9 of the die-supporting lever arm.

As in the operation of the forging machine the cam is rotated, asindicated by the arrow, the lever arm is oscillated; the lever arm'firstmoves in counterclockwise direction against the tension of spring [5 tothe position shown in full lines in Fig. I, and then (as the crest ofthe cam passes from contact with the block 10) the lever arm swings inclockwise direction, under spring tension, and violently strikes thework upon the anvil, as indicated in broken lines. The continu- 5 ousrotation of the cam manifestly will effect the continuous oscillation ofthe lever arm, repeatedly propelling the die 5 against the anvil. It hasbeen proved in service that the hickory helve 8, assembled as describedbetween the hub B, I, I3 and the die 5, provides in the structure thedesired combination of rigidity and elasticity-.-provides an elasticityeffective to protect the metal parts from fatiguing and crystallizing,and yet affords adequate rigidity in the lever arm structure 3 as awhole. While I have specified hickory as the material to use, I do notlimit the invention thereto. There may be other suitable materials thatpossess the peculiar combination of elasticity and sturdiness that isessential to the helve portion of my specific lever-arm construction. I

It will be understood that, while the bore or socket in the rockerportion 13 is of substantially uniform cross section (i. e., the sidewalls of the bore or socket are substantially parallel, as indicated inFig. I), the bore 89 within the die may be tapered, the divergence oftaper being toward the top of the die. And in such case the upper end orhead of the helve will be correspondingly tapered, snugly to fit thebore in the die.

Various modifications are permissible within the terms and intent of theappended claim, and it will be understood that in claiming the structureof the invention I use the words'upwardly 1 and downwardly as Words ofdefinition and not limitation.

I claim as my invention;

In a forging machine including a die, mounted for powerful and rapidreciprocation under the 40 effects of a spring and a rotating cam, thein-.

vention herein described consisting of a die-redownwardly; extending armadapted to 'co-operate with said cam, and a helve formed of relative+ lycompressible and elastic material, said helve at one end carrying saiddiefandat opposite end being compressed under. a pressure of severalthousand pounds in said socket and. thereby united with said socketmember ina shock-ienduring union.

i i LINWO OD M. a

